Machine for cutting or grinding helical gears



Jan. 8, 1935.

A. DE LEEUW 1,986,797

MACHINE FOR CUTTING OR GRINDING HELIQAL GEARS Filed March 9, 1934 I mayHHIIHHIHIH 1 4' 0 1 39 i 3 45 3 4 INVENTOR V ADOLPH L. DELEEUW MATTORNEY Patented Jan. 8, 1935 "f UNI-TEDf sT'hTEis PA ENT omceg 1 i1,9s6,"197 v niem toeeummion GRINDING? l a QEH L C EABS: a a r in l"'A'dblph' n. be; Leeuw, Plainfield, N; J. intentionarthe; 1934,:SerialNo. 714,)48

; V 9- chin (or 51:52)

My. invention: relates toimprovements? in .-machines: for cutting *orgrin'ding helical; gears The present inventionrelates: more iparticularly to' machines ofrtheqgenerall type r shown 1 in my Patent No.I;666,73'7, issued April; 17., 1928. Said patent discloses a machine'adapted' 'toJgrind a plurality of spur gears dispos'edzin: annularseries. The machine has a master driving; gear meshing with a series ofmaster? pinions "each driving a spindle on' which is t mountedu'aisgearblank to be ground; Atu'rntable coaxialwith the master driving gear,*carries ones-or more grinding wheels which, as they "are revolved Ibythe turntable; mesh with'the gearblanks'rsa quentially, the grindingwheels being simultaneously rotated in plane's transverse to theiriplaneof revolution, so as toigrind'" the'iblanks. The table is slowlyfediaxially sothat the. orbit :of each grindingwh'eel-i's a very flathelix' ran d hence each wheel willgin the course of Ia seriesi'of:revolutions; traverse the entire face of each gear employed, whereby adifierenttooth of aclr -gear blank is engaged at successive passageofiaig'rir'idingywheel, so that r at the tend :of: said? :seriesi: ofrevolutions each tooth of each: blank will! have been properly ground.i' I The particular embodiment of my invention illustrated insaidflPatentNoi 1',666,737.;' is not adapted'to grind helical'gearsgbutfinla copend' ing application Serial No'. '631",042, filedAugust 30, 1932, I describe a: machine for: cutting helical gears inwhich rotarycutters are ,used;. saidoutters beingiinclined to conform tothe helix "angle maybe usedforgrindinggear blanksby substitutinggrinding wheels for the cutters and 'driv-f ing said wheelsattherrequisitegrinding-speed;

While said copendi'ng application covers broadly a means for effectingrelative angular progression of the successivepoints'of 'contactTofvacutter-with each tooth space} the specific eznbddi ment described and'illustrated comprises 11 a driving sleeve with nthe masterigear fixedthere to, while the turntable bearing the cutters is splined to "thesleeve; This spline: is I helical so that as" the table isslowly carrieddownward 'by threaded engagement with a feed'screwfit is air--gula'rlydisplaced with respect to the master gear in such degree and insuch direction as-to make the dsiredhelical'cuts in the blanks; v One ofthe drawbacks of the structure specifi cally described in saidj'co'pending" application: lies in thef-difliculty of changing thehelixangle" for different gears; In" fact it is necessarytoreplace thesleeve and the turntable with corresponding partshaving a splinedengagement of different helix angle andalse to substitute new cuttercarriages having cutters disposed at the de'siredhelix angle. Thesechanges are'so radical that they involve'virtually" rebuilding thechange ofhelix angle i I An object of thepresent invention is to providea machine which may Qbe readily set {for grinding or cutting gearslofdifferent helix anglesi re Usually helical gearsaremade in mating pairs,one beingright handed and 'theother left handed, and it isof advantageto beable to cut orf'grind such pairs on the samemachine; It is, there}fore; a further object jofthe presentf'inventiorr to provide a machinewhich" is'f readily convertible from right hand "to left-handjhelicalcuttingor grinding, or' vice versa," with "a minimu n -of q justmentaridre nem 1 v turns with andfl at the" sarne'speed-"asthe sleeve,

while the master gearis drivenby the turntable,

througha roller fixed to said gear and engaging a helicalgroove in acamblock detachably 'secured to the turntable. Inthis way, a desiredadvance or retardation of the gear, with respectto the table; isobtained and may be varied I by the" use otdifferentcamblocks. g Otherobjectsand'advantages oi the invention will appear inthe following'descriptionof a preferred, "embodiment and thereaiter the novelty andscope of'the invention will be pointed out in theclaimsi In'theaccompanying drawing; A v -fF igure- 1 is a viewin sideelevationfoffamachinefembodying my invention, certain portionsofthemachinebeing broken awayand' other portions being shownin section;and 1 Fig. 2 is aface view of a camblock controlling the relativespeedof'thejmaster gearwith respect to the turntable." a a j p pp p "Themachine-shownin the drawing comprises atmain frame 10 having acylindrical bearing portionfll in' which rotates-a sleeve 12. Fittedmachine for each i the particular machine illustrated there are four:

is vertically disposed in the cylinder and engages a slot16 formed inthe sleeve. A worm 17 fixed upon a main drive shaft engages a worm gear18 fixed to or forming an integral part of the sleeve. Concentric withthe cylinder 13 is a fixed screw 19 which engages a nut 20 forming partof the cylinder 13. As the sleeve 12 and cylinder 13 are rotated, theturntable 14 will be fed upward or downward, depending upon thedirection of rotation of 'thezworm 17.

Mounted on the turntable are carriages 22. In

of these carriages. Howeveifl any other number of carriages may be used,but'it'is essential that they be disposed at equal angles apart. Mountedin each carriage is a grinding wheel 23 fixed upon a shaft 24. Eachshaft 24 'carr ies a pulley 25 which is connected by a belt 26 to apulley 27 on the rotary member of a motor 28. The grinding wheels areset at an angle from the vertical which corresponds to the helical angleof the gears to beground: I 1" 1 It will be observed that each carriage:22 has its own individual motor so that the carriage maybeireversed'to, change the angle of the grinding wheel from right handto left hand or vice versa. Eachcarriage .22 isbolted-toa base plate 29whichslides radially in suitable ways 30 formed in the turntable. Thusby means of adjusting .screws 3l-the radial position of each grindingwheel may be adjusted. p I Bolted to the main frame 10 is an annularframe member 33 which is cup-shaped with a rim in the form of a fiatannular shelf-34. Brackets 35 are adjustably mountedon this shelf. Eachbracket supports astackof helical gear blanks 36 which are fixed upon-avertically disposed spindle 37. Each spindle at its lower end has apinion "38 fixed thereto, of the'same pitch diameter as that o f:thegear blankssupported on the upper end ofthe spindle. A'master gear 39engages and drives the pinions 38.- This mastergear is secured to anannulus 40 whichturns in a suitable annulanseat 4 1.formed in theframemember 33. A bracket 42 on the: annulus carriesa roller-43 which engagesa helical cam groove 44 formed in a block 45boltedto-the cylinder 13. v

The operation-of. this machine is very similar to. that described in mycopending application; Tostart with, the turntable is fediupward so thatthe grinding wheels as theyare carried about by the ta lewilljust clearthe extremeupper edges of the gearbla'nks. The machine is shown asgrinding right-hand helicalLgear blanks. When grinding, the turntable isrotated clockwise by its splined engagement with the sleeve ,12 and isfed downward by the screw IQQcausingthe grinding wheels -to follow.a'gradually descending helical orbit and engage the gear blanks on thedifierent spindles .37, successively} Since thegear blanks are rotatedby the master pinion 39 at substa n tially the same peripheral speedasthat of the grindingwheelsintheir orbital motion, there will be'arolling contact of these grinding wheels with the gear blanks; Thenumber of teeth in-the master gear (or in .a segmentv thereof betweengrinding wheel'positions when more than one grinding wheel is used)bears a prime relation to the number of teeth in each master pinionsothat the hunting cog principle isutilized, as-fully describedin myPatent No. 1,666,737 and in said copending application, whereby eachgrinding wheel will engage a different tooth space in each gear blank,at successive engagements therewith unwe l t tqot as ac s havebeeneneaed- A the turntable revolves it is slowly fed downward so that thesuccessive abrasive cuts formed in the gear blanks at each revolution ofthe turntable will be developed across the face of the gear blanks, andbecause at the same time the master gear is given a slightly higherspeed than that of the turntable, owing to the cam groove 44, the gearblanks will turn slightly faster than the grindingw-wheels revolve, so,that thesuccessive abrasive cuts .will'be developed helically across theface of the gear blanks.

It will be understood, of course, that the gear blanks may be ofdifferent diameters and it is gmerely essential that they have the sameperipheral speed as that of the grinding wheels in their orbitalmovement with a slight increment or decrement depending upon the hand ofthe helix angleof the gear blanks. When it is de-- sired to reverse thegrinding angle for gears of reverse hand the carriages 20 are unboltedand turned through an angle of180 :degrees and then bolted again to thebase plate "29 so that the grinding wheels will be disposedat a reversedangle and thenthe cam-block 45 is replaced with another having a helicalgroove .44 of opposite hand. With thesesimplechanges the machine is.thenqincoridition to grind helical'gears of re- .verse' hand.

vWhile I-havereferred to :this machine as a grinding machine and to thetools 23 as grinding wheelsit will be understood that the same machinemay be employed for roughing out-or finish cutting gear blanks and thatcircular cutters may be'substituted for 'the grinding wheels 23.

For this reason in the claims I shall use the term forming tool toinclude not only grinding Wheels but also cutters. Obviously, otherchanges may; be made in form, construction and arrangement' 'of variousparts without departing from thespirit and scope of thefollowing claims,and

consequently the particular embodiment described isito be taken asillustrative andnot limitative of myinvention.

":1; A'machine'of the character described, com

prising a master'gear,:an' orbital series 'Of'pinions meshing therewith,means for securing a helicaLgear blank coaxially rigid with each pinion,a turntable, arotary forming tool mounted thereon, means for producing ahelical motion of the "turntable and tool with respect to the gearblanks to progres'sively cutall the teeth of each blankgand a drivingconnection between the turntable and the master. gear adapted to givethe master gear :a slightly different'speed' of rotationfrom that of theturntable so as to effect ahelical development of the tool cuts acrossthe face of the blank, said driving connection comprising a detachableand replaceable member for'chan'gin'g'the helix angle of the cuts. 2. Amachineof the character described, comprising'a mastergear,an'orbital"series ofpinions meshing therewith, means for securing ahelical gear blank coaxially rigid with each pinion, a turntable,a-rotary forming tool mounted thereon, means for producing a helicalmotion of the turntable 'and'tool with respect to the gear blanks toprogressively cut all the teeth of each blank, and a driving connectionbetween the turntable and the master gear adapted to give the-mastergear a slightly diiferent speed of rotation from that'of the turntableso as to eifect a .helical development of the tool cuts across the faceof the blank, said driving con-. nectionrcomprisinga cam block-formedwith a idetaicheblyaconnectedi tm the turntable and a roller engagingthe groove-and dat ried by tfie gea a l rt:t'aiiifng and "simultanecuslyadvancing" the turntableaxially with respect to thedrame, a master gearcoaxial' with-the turntable-and rotatabl'e in a fixed plane*with--respect tothe-f'rame, a series ei 'master pinions 'meshiiig withthegear, means for -mounting a helicaligeair blank coaxiall'y rigid witheach-pinion; each blank being of" the same pitch diameter as the 'pinibnwith which it is ass tiateer a ro'tfar forming tool mounted on the?able-"imposition toengage and cutqthe blanks successively duringrotation of the turm were, a the gear ratio between the master gear andthe pi'iiiensbeing such as to bring different 2G tooth -spaces ofeachblank' successively into engagement with-'- t'he -tool means forrotating the 001 am inclined planecoinciding Witt-1- the-{deir'igcbr'ineetibn betweerr-the master gear and the turntable,- saidciconnection bein'gj'controll'e'd by series of master pinions withthegear, means for mounting a helical gear blank coax-,

ially' ri'gid witheael'i pin-ion, each blank being of the same pitchdiameter as the pinion with which it is associated, a rotary formingtool mounted on the table in position toengage and cut the blankssuccessively during rotation of the turntable, the gear ratio of themaster gear and the pinions being such as to bring difierent toothspaces of each blank successively into engagement with the tool, means,for rotating the tool in an inclined plane coinciding with the desiredhelix angle of the gear blanks, and a driving connection between themaster gear and the turntable, said connection comprising a pair ofinterengaging members carried by said turntable and said master gearrespectively, the engaging surface of one of the members being helicallydisposed so that by reason ofthe axial movemerit of the turntable themaster gear will be given a slightly different speed of rotation fromthat of the turntable to effect a development of the points ofengagement of the tool with each blank in the desired helical direction.

5. A machine of the character described, comprising a main frame, aturntable, means for rotating and simultaneously advancing the turntableaxially with respect to the frame, a master gear coaxialwith theturntable and rotatable in a fixed plane with respect to the frame, aseries of master pinions meshing with the gear,

means for mounting a helical gear blank coaxially rigid with eachpinion, eachj blank being of the same pitch diameter as the pinionwithwhich it is associated, a rotary forming tool mounted on the table inposition to engage and cut the blanks successively during rotation ofthe turntable, the gear ratio between the master gear and the pin ionsbeing suchas to bring different tooth spaces of each's blanksuccessively intoiengagementcwith theatoolgw meansi fomz rotating gthe-.ttool im antimclined plamer coincidingztwithl the x desiredt helixangle: Of th'BE gear" blanks; and a drivinguconnecw tionbetweenthe-master: geanjand .thevturntabler; said connection comprising a pairof interengage ing: members :cannied: by said; turntablettand saidmastersgear respectively, onesotlthe:membensacorr;

sisting: of a detachable cam: blocklforrned 1withta helicallydisposed:cam; :groove; 0 and; J'the: other member 1 consisting Off a 11701183engaging the g1ioove;-: the latter: beingzrso disposed that; by: rea.-;son: or the axial movement of the turntable: the master gear willlbegiven .a slightly: differentspeed of? rotations fnomi that :of.therturntable to; efitict a. development of: the. pointszof engagement;of l the tool: with each blank the. l desired helical .di.-- rection...Q i P l 1w 6. Asmachineg of. the "character describem. come pri'singr'amainifra-me; aturntable,@meanstfomros a tasting; and; simultaneouslyadvancing .the turne table axially with. respect to-therframeg a mastergear. coaxialgwith theaturntablezand; rotatable! ima fixe'di plane withrespect .to; the frame, a-Jseries: of master pinions meshingwith thegearpmeans for mounting a helical gear blank :coaxial'lyrigid with eachpinion, each I blank being" of :thea same epitch diameter asthelxpinionwwith whichrit, is associated, a rotary forming :tooh mountedthe table. :in position to engagesa'nd cut the blanks: successivelyduringrotationloft the turntable-,1 the: gear, ratio betweeni :therriaster gear and: the. rpinionsebeing suclrs as J to bring; different;tooth spaces of ;each blankysuceessively: into; engagement with". the

tools; meansu for; rotating; the: tools an-inclined plane. coinciding)with stile-desired helix :a l l c thege'emcblanks,*a;camblockgdetachabiyamo on theltumtableiand formedawithzaz helical and faroliemonzthemasteh gfia llen a zi ggwiid groove, the latter being sodisposed that by reason of the axial movement of the turntable themaster gear will be given a slightly difierent speed of rotation fromthat of the turntable to efiect a development of the points ofengagement of the tool with' each blank in the desired helicaldirection.

'7. A machine of the character described, comprising a main frame, aturntable, means forro-' tating and simultaneously advancing theturntable axially with respect to the frame, a master gear coaxial withthe turntable and rotatable in a fixed plane "with respect to the frame,a series of master pinions meshing with said gear, means for mounting ahelical gear blank coaxially rigid with each pinion, each blank being ofthe same pitch diameter as the pinion with which it is associated, 'aplurality of rotary forming tools mounted on the table in position toengage and cut the blanks successively during rotation of the turntable,means for rotating each tool in an inclined plane coinciding with thedesired helix angle of the gear blanks, the tools being disposed atequal angles apart on the table, the number of teeth in a segment of themaster gear embraced within an angle equal to the spacing of the toolsbearing a prime ratio to the number of teeth of each master pinion, anda driving connection between the master gear and the turntable, saidconnection comprising a pair of engagmember consisting of a rollerengaging the groove, the groove being so disposed that by reason of theaxial-movement of the turntable the master gear will be given a slightlydifferent speed of rotation from that of the turntable to effect prisinga main frame, a turntable, means for rotatingandsimultaneously advancingthe turntable axially with respect to the frame, a master gear coaxialwith the turntable and rotatable in a fixed plane with respect to theframe, a series of master pinions meshing with said gear, means formounting a helical gear blank coaxially rigid with each pinion, eachblank being of the same pitch diameter as the pinion with which it isassociated, a plurality of I rotary forming tools mounted on the tablein position to engage. and cut the blanks successively during rotationof the turntable, means for rotating each tool, the plane of rotation ofthe tool being adjustable to coincide with the desired helix angle ofthe gear blanks,

the tools being disposed at equal angles apart on the table, the numberof teeth in a segment of the master gearembraced within an angle equaltothe spacing of the tools bearing a prime ratio to the number of teethof each master pinion, and adriving connection between the master gearand the'turntable, said connection comprising a pair of..interengagingmembers carried by said I turntable and said master gear respectively,one

of the members consisting of a detachable cam block formedwith ahelically disposed groove and the other member consisting of a rollerengaging the groove, the groove" being so disposed that by reason of theaxial movement of the turntable the I master gear will be givenaslightly different speed of rotation from that of the turntable toefiect a development of the points of engagement of the tools with eachblank in the desired helical direction.

9. A machine of the character described, comprising a main frame, aturntable, means for rotating and simultaneously advancing the turntableaxially with respect to the frame, a master gear coaxial with theturntable and rotatable in afixed plane with respect to the frame, aseries of master pinions meshing with said gear, means for mounting ahelical gear blank coaxially rigid with each pinion, each blank being ofthe same pitch diameter as the pinion withwhich it is as.- sociated, acarriage mounted on the table, a roe tary forming tool mounted in thecarriage in position to engage and cut the blanks successively duringrotation of the turntable, the plane of rotation of the tool beingangled to the helix angle of the blanks, a motor on the carriage forrotating the tool, the carriage being reversible on the table to reversethe angle of the tool, the gear ratio between the master gear and themaster pinionsybeing such as to bring different tooth spaces of eachgear blank successively into engagement with the tool, a drivingconnection between the master gear and the turntable comprising a pairof interengaging members carried by said turntable and said master gearrespectively, one of said members consisting of a detachable cam blockformed with a helically disposedcam groove and the other memberconsisting of a roller engaging the groove, the groove being so disposedthat by reason of the axial movement of the turntable the master gearwill be given a slightly difierent speed of rotation from that of theturntable to effect a development of the points of engagement of thetool with each blank in the desired helical direction.

ADOLP'H L. DEV LEEUW.

